Survey and Identification of Root-Knot Nematode Species (Meloidogyne spp.) in Vegetable Greenhouses Using Morphological and Molecular Markers

Abstract

Meloidogyne spp. are among the most destructive plant-parasitic nematodes affecting greenhouse vegetable production systems worldwide, causing severe yield losses and quality deterioration. The present study was conducted to survey and identify root-knot nematode species infecting vegetable crops in greenhouse conditions using morphological and molecular markers. Soil and root samples were collected from symptomatic plants exhibiting stunting, chlorosis, wilting, and characteristic root galling from different greenhouse locations. Nematodes were extracted using standard methods and examined for morphological and morphometric characteristics, including perineal pattern structure of females, juvenile body measurements, and stylet morphology. Based on preliminary morphological identification, multiple populations of root-knot nematodes were detected. For molecular characterization, genomic DNA was extracted from individual females, and species-specific PCR assays along with sequencing of conserved gene regions were performed. Sequence analysis and phylogenetic comparisons confirmed the presence of distinct Meloidogyne incognita and related species complexes in the surveyed greenhouse systems. The study revealed variability in species distribution across different greenhouse environments, likely influenced by cropping history, soil conditions, and management practices. The integration of morphological and molecular approaches ensured accurate species identification, overcoming limitations associated with traditional taxonomy alone. These findings emphasize the importance of precise nematode diagnostics for effective management in protected cultivation systems. Understanding the distribution and diversity of root-knot nematodes is essential for developing targeted management strategies, including resistant cultivars, crop rotation, and biological control options. The study provides valuable baseline information for nematode surveillance and contributes to sustainable greenhouse vegetable production by supporting integrated nematode management programs.